37 research outputs found

    Compound tool construction by New Caledonian crows

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    The construction of novel compound tools through assemblage of otherwise non-functional elements involves anticipation of the affordances of the tools to be built. Except for few observations in captive great apes, compound tool construction is unknown outside humans, and tool innovation appears late in human ontogeny. We report that habitually tool-using New Caledonian crows (Corvus moneduloides) can combine objects to construct novel compound tools. We presented 8 naive crows with combinable elements too short to retrieve food targets. Four crows spontaneously combined elements to make functional tools, and did so conditionally on the position of food. One of them made 3- and 4-piece tools when required. In humans, individual innovation in compound tool construction is often claimed to be evolutionarily and mechanistically related to planning, complex task coordination, executive control, and even language. Our results are not accountable by direct reinforcement learning but corroborate that these crows possess highly flexible abilities that allow them to solve novel problems rapidly. The underlying cognitive processes however remain opaque for now. They probably include the species' typical propensity to use tools, their ability to judge affordances that make some objects usable as tools, and an ability to innovate perhaps through virtual, cognitive simulations

    5 Miejsce radioterapii w leczeniu chorych na pierwotne chłoniaki śródpiersia o wysokim stopniu złośliwości histologicznej

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    MateriałW latach 1991–1998 leczono w Centrum Onkologii – Instytucie im. Marii Skłodowskiej – Curie w Warszawie 31 chorych na pierwotnego chłoniaka śródpiersia o wysokim stopniu złośliwości z dużych komórek B (I-IV stopień klinicznego zaawansowania), w tym 16 kobiet i 15 mężczyzn w wieku od 17 do 59 lat (media 30 lat).MetodaWszyscy chorzy zostali poddani chth (30 chorych wg programu: CHOP –media 6 kursów, 1 chorzy wg programu Pro-MACE-MOPP-6 kursów). U 27 (87%) chorych uzyskano na leczenie –Cr u 9 (29%) chorych, Pr u 18 (58%) chorych. U 1 chorego, u którego wystąpiła szybka progresja po leczeniu I rzutu; po zastosowaniu chth drugiego rzutu uzyskano CR.Radioterapię przeprowadzono u 25 (81%) chorych; u 18 (58%) jako leczenie uzupełniające po chth; u 2 chorych jako leczenie 1 rzutu; u 5 chorych jako leczenie paliatywne z powodu progresji zmian po chamioterapii. 21 chorych było napromienianych tylko na śródpiersie, 4 chorych również na inne okolice pierwotnie zajęte. Dawka całkowita wynosiła 36–48 Gy/t (media 40 Gy/t) we frakcjonowaniu konwencjonalnym (1,8–2 Gy/t). U 4 chorych, u których stwierdzono progresję w OUN przeprowadzono napromienianie mózgu (36–40,6 Gy/t) z dokanałowym podawaniem cytostatyków (MTX+DX).WynikiSpośród chorych, którzy uzyskali PR po chth, u 9 uzyskano CR po radioterapii, uzyskując łącznie CR u 18 (58%). W okresie od 3 do 79 miesięcy (media 18 miesięcy), u 8 chorych (1 chory z CR, 7 chorych z PR) wystąpiła progresja choroby. Zmarło 10 chorych, 1 chora została utracona z obserwacji z aktywną chorobą.WnioskiSkuteczniejszym sposobem leczenia chorych na pierwotne chłoniaki śródpiersia o wysokim stopniu złośliwości z dużych komórek B jest leczenie skojarzone: chemioterapia z uzupełniającym napromienianiem. Zastosowanie radioterapii zwiększa liczbę uzyskiwanych CR, jednak wymaga to potwierdzenia na większej grupie chorych

    Inducible cAMP Early Repressor (ICER) and Brain Functions

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    The inducible cAMP early repressor (ICER) is an endogenous repressor of cAMP-responsive element (CRE)-mediated gene transcription and belongs to the CRE-binding protein (CREB)/CRE modulator (CREM)/activating transcription factor 1 (ATF-1) gene family. ICER plays an important role in regulating the neuroendocrine system and the circadian rhythm. Other aspects of ICER function have recently attracted heightened attention. Being a natural inducible CREB antagonist, and more broadly, an inducible repressor of CRE-mediated gene transcription, ICER regulates long-lasting plastic changes that occur in the brain in response to incoming stimulation. This review will bring together data on ICER and its functions in the brain, with a special emphasis on recent findings highlighting the involvement of ICER in the regulation of long-term plasticity underlying learning and memory

    Inhibitory Role of Inducible cAMP Early Repressor (ICER) in Methamphetamine-Induced Locomotor Sensitization

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    BACKGROUND: The inducible cyclic adenosine monophosphate (cAMP) early repressor (ICER) is highly expressed in the central nervous system and functions as a repressor of cAMP response element-binding protein (CREB) transcription. The present study sought to clarify the role of ICER in the effects of methamphetamine (METH). METHODS AND FINDINGS: We tested METH-induced locomotor sensitization in wildtype mice, ICER knockout mice, and ICER I-overexpressing mice. Both ICER wildtype mice and knockout mice displayed increased locomotor activity after continuous injections of METH. However, ICER knockout mice displayed a tendency toward higher locomotor activity compared with wildtype mice, although no significant difference was observed between the two genotypes. Moreover, compared with wildtype mice, ICER I-overexpressing mice displayed a significant decrease in METH-induced locomotor sensitization. Furthermore, Western blot analysis and quantitative real-time reverse transcription polymerase chain reaction demonstrated that ICER overexpression abolished the METH-induced increase in CREB expression and repressed cocaine- and amphetamine-regulated transcript (CART) and prodynorphin (Pdyn) expression in mice. The decreased CART and Pdyn mRNA expression levels in vivo may underlie the inhibitory role of ICER in METH-induced locomotor sensitization. CONCLUSIONS: Our data suggest that ICER plays an inhibitory role in METH-induced locomotor sensitization

    Deregulation of CREB Signaling Pathway Induced by Chronic Hyperglycemia Downregulates NeuroD Transcription

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    CREB mediates the transcriptional effects of glucose and incretin hormones in insulin-target cells and insulin-producing β-cells. Although the inhibition of CREB activity is known to decrease the β-cell mass, it is still unknown what factors inversely alter the CREB signaling pathway in β-cells. Here, we show that β-cell dysfunctions occurring in chronic hyperglycemia are not caused by simple inhibition of CREB activity but rather by the persistent activation of CREB due to decreases in protein phophatase PP2A. When freshly isolated rat pancreatic islets were chronically exposed to 25 mM (high) glucose, the PP2A activity was reduced with a concomitant increase in active pCREB. Brief challenges with 15 mM glucose or 30 µM forskolin after 2 hour fasting further increased the level of pCREB and consequently induced the persistent expression of ICER. The excessively produced ICER was sufficient to repress the transcription of NeuroD, insulin, and SUR1 genes. In contrast, when islets were grown in 5 mM (low) glucose, CREB was transiently activated in response to glucose or forskolin stimuli. Thus, ICER expression was transient and insufficient to repress those target genes. Importantly, overexpression of PP2A reversed the adverse effects of chronic hyperglycemia and successfully restored the transient activation of CREB and ICER. Conversely, depletion of PP2A with siRNA was sufficient to disrupt the negative feedback regulation of CREB and induce hyperglycemic phenotypes even under low glucose conditions. Our findings suggest that the failure of the negative feedback regulation of CREB is the primary cause for β-cell dysfunctions under conditions of pathogenic hyperglycemia, and PP2A can be a novel target for future therapies aiming to protect β-cells mass in the late transitional phase of non-insulin dependent type 2 diabetes (NIDDM)

    Early phase of plasticity-related gene regulation and SRF dependent transcription in the hippocampus

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    Hippocampal organotypic cultures are a highly reliable in vitro model for studying neuroplasticity: in this paper, we analyze the early phase of the transcriptional response induced by a 20 \ub5M gabazine treatment (GabT), a GABA-Ar antagonist, by using Affymetrix oligonucleotide microarray, RT-PCR based time-course and chromatin-immuno-precipitation. The transcriptome profiling revealed that the pool of genes up-regulated by GabT, besides being strongly related to the regulation of growth and synaptic transmission, is also endowed with neuro-protective and pro-survival properties. By using RT-PCR, we quantified a time-course of the transient expression for 33 of the highest up-regulated genes, with an average sampling rate of 10 minutes and covering the time interval [10 3690] minutes. The cluster analysis of the time-course disclosed the existence of three different dynamical patterns, one of which proved, in a statistical analysis based on results from previous works, to be significantly related with SRF-dependent regulation (p-value<0.05). The chromatin immunoprecipitation (chip) assay confirmed the rich presence of working CArG boxes in the genes belonging to the latter dynamical pattern and therefore validated the statistical analysis. Furthermore, an in silico analysis of the promoters revealed the presence of additional conserved CArG boxes upstream of the genes Nr4a1 and Rgs2. The chip assay confirmed a significant SRF signal in the Nr4a1 CArG box but not in the Rgs2 CArG box

    Compound tool construction by New Caledonian crows

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    The construction of novel compound tools through assemblage of otherwise non-functional elements involves anticipation of the affordances of the tools to be built. Except for few observations in captive great apes, compound tool construction is unknown outside humans, and tool innovation appears late in human ontogeny. We report that habitually tool-using New Caledonian crows (Corvus moneduloides) can combine objects to construct novel compound tools. We presented 8 naïve crows with combinable elements too short to retrieve food targets. Four crows spontaneously combined elements to make functional tools, and did so conditionally on the position of food. One of them made 3- and 4-piece tools when required. In humans, individual innovation in compound tool construction is often claimed to be evolutionarily and mechanistically related to planning, complex task coordination, executive control, and even language. Our results are not accountable by direct reinforcement learning but corroborate that these crows possess highly flexible abilities that allow them to solve novel problems rapidly. The underlying cognitive processes however remain opaque for now. They probably include the species’ typical propensity to use tools, their ability to judge affordances that make some objects usable as tools, and an ability to innovate perhaps through virtual, cognitive simulations
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